1. Field of the Invention
The present invention relates to a tunable inter-digital capacitor (IDC) and a method of manufacturing the same. More particularly, the present invention relates to a tunable IDC capable of increasing tunability thereof and reducing drive voltage by concentrating a fringing electric field generated at the edge of an IDC electrode in a dielectric material to equalize electric field distribution, and a method of manufacturing the same.
2. Description of the Related Art
In general, an IDC utilizes a material such as a ferroelectric or paraelectric material whose permittivity varies depending on an applied electric field.
Since a conventional tunable IDC has electrodes exposed on a tunable dielectric material, i.e., in the air, a considerable part of the applied electric field is distributed in the air and only a part thereof exists in the dielectric material. In addition, the part existing in the dielectric material is not uniformly distributed.
Therefore, the conventional tunable IDC has some drawbacks in that it has low tunability and requires high direct current (DC) bias in a high frequency region.